Not only do they display sympathy toward mutilated and helpless friends, but also toward healthy individuals who may accidentally get into trouble and need assistance. Belt, while watching a column of Eciton hamata, placed a stone upon one of them to secure her. The next ant in line, as soon as she discovered the condition of her friend, ran hurriedly backward and communicated the intelligence to the others. "They rushed to the rescue; some bit at the stone and tried to move it, others seized the prisoner by the legs and tugged with such force that I thought the legs would be pulled off; but they persevered until they got the captive free. I next covered one up with a piece of clay, leaving only the ends of its antennæ projecting. It was soon discovered by its fellows, which set to work immediately, and by biting off pieces of the clay soon liberated it."
At another time he found a few of the same ants passing along at intervals. He buried one beneath a lump of clay, leaving only the head protruding. A companion soon discovered her and tried to release her. Finding this to be impossible, she hurried away. Belt thought that she had abandoned the unfortunate prisoner, but she had only gone for assistance, and soon returned accompanied by a dozen companions, which made directly for the imprisoned ant and soon set her free. "I do not see how," says Belt in conclusion, "this action could be instinctive. It was sympathetic help, such as man only among the higher mammalia shows. The excitement and ardor with which they carried on their unflagging exertions for the rescue of their comrade could not have been greater if they had been human beings."[53] I have buried Lasius flavus beneath sand, and in every instance, sooner or later, they have been dug out by their companions.
Rev. Mr. White has noticed the same sympathetic help among F. sanguinea.[54] Lubbock noticed in one of his nests of F. fusca, Jan. 23, 1881, an ant lying on her back and unable to move. She was unable even to feed herself. Several times he uncovered the part of the nest where she was. The other ants at once carried her to the covered part. "On March 4," says he, "the ants were all out of the nest, probably for fresh air, and had collected together in a corner of the box; they had not, however, forgotten her, but had carried her with them. I took off the glass lid of the box, and after a while they returned as usual to the nest, taking her in again. On March 5th she was still alive, but on the 15th, notwithstanding all their care, she was dead."[55]
Dr. Stimson Lambert of Owensboro, Kentucky, a careful and accurate observer, informs me that he has frequently observed the large red ants (F. rufa) helping their mutilated or crippled companions.
Ants exhibit another emotion that shows the high development of their psychical or emotional nature. In the tender watchfulness and care of their young they are surpassed by no living creature. As soon as the young ant bursts its pupa case, it is carefully assisted into the world by its foster-mothers. These foster-mothers clean it with their tongues, gently going over the entire surface of its body, and then feed it. The young ant is conducted by them throughout the whole nest, and shown all the devious passageways and corridors. When it makes its first visit into the outside world, it is always accompanied by several chaperons. This parental love, if I may use the expression, is even extended to the unhatched eggs. If an ants' nest is disturbed by a stroke of a spade or hoe, the little inhabitants will at once begin to remove eggs, pupæ, and young to a place of safety.
This parental love is even evinced by insects who never see their offspring. The butterfly uses the utmost care in selecting a suitable leaf on which to deposit her eggs. She selects one that will be nourishing food for the larvæ when hatched out, and, after carefully observing whether it is preoccupied by the eggs of some other butterfly (in which case she abandons it), she proceeds to deposit her eggs. "Having fulfilled this duty, from which no obstacle short of absolute impossibility, no danger however threatening, can divert her, the affectionate mother dies."[56]
The gadfly uses a like forethought in selecting a place for her eggs. The larvæ of the gadfly (Œstrus equi) are developed in the stomach of the horse, so the provident mother attaches the eggs to the hairs of the foreleg between the knee and the shoulder, a place the horse is almost certain to lick with his tongue and, in this manner, convey the eggs to his stomach, where they are hatched out. The breeding place of certain of the ichneumons is the body of a caterpillar. The ichneumon may be seen busily searching the bushes for her victim. When she finds it, she inserts her ovipositor into its body and lays her egg. If some other ichneumon has preceded her, she recognizes the fact at once, and will not deposit her egg, but will go in search of another grub. When the egg is hatched, the larva feeds on the body of its host, carefully avoiding the vital organs. The caterpillar retains just enough vitality to assume the pupa state, and then dies. The chrysalis discloses, not a butterfly, but an ichneumon.
The mason wasp (Epipone spinipes) builds its cells and lays its eggs, one in each cell. It then hunts and procures spiders, which it deposits in the cells and then seals the openings. These spiders are not killed outright, but are partially paralyzed by the sting of the wasp. The insect thus secures for her young a supply of fresh food. This wasp not only knows the difference between the eggs that will produce female young, but she also makes this knowledge useful. She always supplies the females with more spiders than she does the males. The females are larger and require more food, hence the discrimination. All of this care and forethought is expended on young which the mother will never see. Human love cannot give greater evidences of complete unselfishness.
I once removed a ball of eggs from the web of a spider. The mother clung tenaciously to her treasure, and, when I tried to remove her with a pair of forceps, she bit fiercely at the steel blades of the instrument. In her great love for her offspring she lost all sense of fear. Time and again I removed her several inches from the eggs; she would run about in a distracted way, for all the world like a mother who had lost her baby, until she found the ball of eggs. She would then seize it and attempt to remove it to a place of safety. The naturalist, Bonnet, put a spider and her bag of eggs in the pit of an ant-lion. The myrmeleon seized the egg-bag and tore it away from the spider. Bonnet forced the spider out of the pit, but she returned and chose to be dragged in and buried alive rather than leave her eggs.[57]
Earwigs lay their eggs, and then incubate them after the manner of the hen. When the young are hatched out, the proud mother leads forth the brood and shows unmistakable pride and affection in her children. On one occasion, when a storm was coming up, I saw an earwig marshal her troop of young ones, and lead them to a place of safety beneath the bark of a tree.